Diagnosis of death by neurological criteria (DNC) is a construct which has been part of the British medico-legal landscape for nearly half a century. This book examines the factors behind its emergence, and discusses the various changes that took place in the last few decades that culminated in the current definition and clinical criteria for determining brain-based death. It highlights the continuities and discontinuities in practice, and the impact they have on the issue of withdrawal of mechanical ventilation in intensive care units and on the field of organ transplantation. The book also explores the law’s response to the introduction and development of DNC in clinical practice. It demonstrates how the legitimacy of the definition and criteria used by the medical profession were forged in the courtroom rather than in Parliament. It documents why case law were introduced in court, and assesses whether organ donation was a consideration in the deliberations. It will be emphasised that courts have given insufficient consideration to requests made in recent cases to consider a broader range of methods to determine death. Those pleas were made on the grounds that the definition and criteria used in the UK are dissimilar to those used in other jurisdictions that also adopt DNC; and that faith communities have a different understanding of death. By taking a close look at those other approaches before highlighting the inherent limitations of the courtroom as the forum that confers DNC its legitimacy, the book puts forward the argument that the democratic process should be engaged.